flutter - 如何在 Flutter 中创建和使用响应式主题？

Question

我MediaQuery.of() called with a context that does not contain a MediaQuery.在尝试从以下位置访问 MediaQuery 时得到MaterialApp：

return new MaterialApp(
  title: 'Flutter Demo',
  theme: getTheme(MediaQuery.of(context)),
  home: new Container(),
);

Answer 1

改为使用builder。MaterialApp这样您就MediaQuery可以MatetialApp在Theme.

new MaterialApp(
  builder: (context, child) {
    return new Theme(
      data: getTheme(MediaQuery.of(context)),
      child: child,
    );
  },
  home: new ChatScreen(),
),

Answer 2

return new MaterialApp(
      title: 'Flutter Demo',
      theme: getTheme(new MediaQueryData.fromWindow(ui.window)),
      home: new Container(),
    );

谢谢君特 :)